CD Projekt RED, the Polish developer behind The Witcher series and the Good Old Games (gog.com) online store today held its big announcement event celebrating 4 years of GOG.

The majority of the event revolved around the day’s biggest announcement that GOG will now be offering many of its games on Mac OS. Starting today, 50 GOG games are available, 28 of which have never been available for Mac before. GOG is well-known for offering older PC games from the 80s and 90s as well as offering all of their games without any digital rights management (DRM).

One of the games that will be offered for Mac is CD Projekt RED’s latest hit RPG The Witcher 2: Assassins of Kings Enhanced Edition. The title is now available via GOG or Steam, and is being offered for only $22.49 for the next 48 hours. The Witcher Enhanced Edition is also being made available during that time for $5. Customers who already own The Witcher 2 for will be given access to a copy for Mac

In fact, all of Mac games offered on GOG, including The Witcher 2, will be hybrid, meaning customers will get both the PC version and the Mac version for one price. Also, the games will not have any DRM, allowing customers to use and copy the games as they see fit.

A native OS X downloader app was released to coincide with the announcement, allowing Mac users to speed the download of their purchased titles.

As a celebration of GOG’s 4th birthday, the company has teamed up with Interplay to offer dozens of classic titles in an “indie bundle” format. For a limited time, customers on GOG will be able to pay whatever they want for 8 Interplay games, including Shattered Steel, Screamer, and Evolva. Customers paying over the average will get 20 Interplay games, including Descent 3, Earthworm Jim 3D, and Fallout. Those paying $35 will get all 32 Interplay games available through GOG, including Fallout 2, Fallout: Tactics, Descent 1 &2, and Earthworm Jim 1&2. The total collection comes with tons of extra goodies, such as soundtracks, manuals, wallpapers, The Fallout Bible, and more.